The 1987 Schwarzenegger semi-classic “Predator” spawned a sequel, called “Predator 2,” plus crossover films “Alien vs Predator” and “Aliens vs Predator: Requiem,” not to mention a comic book. The new sequel, simply called “Predators,” ignores all of those follow-ups and takes the story back to its jungle roots. This proves to be wise. I wouldn’t say “Predators” is a great movie, but it’s good enough, executing its simple premise with tension and testosterone to spare.

And what is that premise? Adrien Brody sums it up 30 minutes into the film: “This planet is a game preserve. And we’re the game.” BOO-YEAH! (That line’s in the trailer, too.) You see, while previous Predators — alien creatures with superior hunting skills — came to Earth and harassed military men in the jungles of Central America, the current Predators have instead abducted a handful of humans and dropped them on another planet, to be hunted for sport and entertainment.

There are eight of them. Hardly anyone’s name is used, so we’ll pretend they have the same names as the actors who play them. Adrien Brody, doing what sounds like an impression of an action hero, is the most famous person in the cast and is therefore the “protagonist,” though that term has very little relevant meaning here. He’s an ex-military mercenary. Alice Braga, also a soldier, is the requisite sexy hardass female. Oleg Taktarov and Mahershalalhashbaz Ali have military training as well. Then there’s Walton Goggins as a comically crude convict, Danny Trejo as an enforcer for a Mexican drug cartel, and Louis Ozawa Changchien as a yakuza gangster. Finally, Topher Grace is for some reason in this movie, and for some reason he plays a doctor.

These folks, all strangers to one another, find themselves dropped via parachute into a steaming jungle on what they soon realize is an alien planet. (They take this in stride.) Under Brody’s gruff, pompous leadership, they figure out what’s happening and begin the arduous process of defending themselves, striking back against their hunters, and being killed one at a time.

Robert Rodriguez conceived the basic story some 15 years ago but has only now been able to get it made. He serves as producer; the screenplay is by hotshot newcomers Alex Litvak and Michael Finch, who already have a handful of other scripts in development. Occupying the director’s chair is Nimrod Antal, a kindred spirit of Rodriguez’s whose “Vacancy” and “Armored” were genre films that turned out better than a lot of their genre-mates do — which describes “Predators,” too. It’s reasonably tense and creepy, if never outright “scary.” It’s intense without taking itself too seriously; at the same time, it has a sense of humor but doesn’t get too campy. Antal, who is 36, is part of the generation that grew up with movies like this, and he’s savvy about what makes them work without falling into self-parody.

For the most part, anyway. The stop-and-regroup scenes between action sequences, where the characters have hushed conversations about what they’ll do if they ever get back home, are strained and perfunctory. The film doesn’t know when to quit, either, reaching a perfectly good climax and then dragging itself along for another 10 minutes. You could make a strong case for the whole thing being more of a rehash of “Predator” than a sequel to it — and thus wholly unnecessary — but let’s not be churlish. In the wasteland that the summer of 2010 has turned out to be, we’ll take our breezy action pictures however we can get them.